The name "octopus"
means literally "eight feet" and this
animal does indeed have eight arms, joined at
their bases by a web and surrounding a beaked
mouth. Although some specimens may reach a span
of 10 feet, the average is approximately 3 feet.
This octopus has a world-wide
distribution, being found in all oceans (except
the Arctic), as well as the Mediterranean and
Caribbean seas. It lives in tropical,
subtropical, and temperate waters between the
surface and a depth of 300 to 500 feet.
The arms are very sensitive to
touch and taste, and the eyes are well developed.
The importance of vision is reflected in the
octopus's outstanding ability to change color.
This is done with two kinds of chromatophores
(pigment cells) in the skin that vary in color
according to how much they are expanded or
contracted. One kind varies from black to
red-brown and the other from red to pale
orange-yellow. Beneath these chromatophores is a
layer of small bodies known as iridocytes that
reflect white light or give a blue or green by
refraction.The variation in appearance is also a
matter of posture and of general texture. The
arms may be extended, tucked underneath, or
curled stiffly back over the body as armor and
the suckers may be out of sight or protruded to
give the arms a wavy outline. By suitable
adjustments in color, posture and texture an
octopus can merge completely with its background,
and it can do so very quickly. What's more, the
octopus's "quick change" is done
intentionally, with a specific result intended.
That is, rather than simply take on the color,
texture, etc. of its background, an octopus may
also use its camouflage ability to
"create" a lure to attract prey. It can
also, if necessary, take on the coloring and/or
posture of a poisonous animal in order to deter
potential predators. Observations have also shown
that an octopus will take on various colors,
textures, etc. to express moods, and some have
been seen changing colors, etc. for no apparent
reason at all.
A bottom-dwelling animal, the
octopus makes its home in a hole or rock crevice
in shallow water. By day, it spends most of its
time hidden in its lair. When outside, it creeps
about on its arms most of the time, using its
suckers to grip, though it can also swim. It
usually swims headfirst with its arms trailing,
by blowing water out through its siphon. It is a
solitary and territorial animal, with individuals
coming together only for breeding purposes.
The octopus does most of its
hunting at night, emerging from its lair to seek
crabs, crayfish, and other molluscs. It catches
most of its prey by stealth. Using its camouflage
abilities to blend in with its surroundings, it
waits for prey to pass by and then seizes it with
its long arms. The arms are powerful and
flexible, with two rows of suckers that help it
grip its prey. Once caught the prey is stunned
with a secretion of nerve poison. To stalk
lobsters and other potentially dangerous prey,
the octopus squirts ink into the water to form a
screen, from behind which it creeps up on its
The octopus is preyed upon by moray and conger
eels, dolphins, and sharks. Whenever possible,
the octopus will escape from its predators by
shooting a jet of water through its body to
create a burst of speed.
The octopus's ink sac also helps it avoid
predators. It releases a disorienting black cloud
that is accompanied by another secretion to dull
the attacker's sense of smell.
to mating, the male approaches the female, who
fends him off for a while, but then submits to
him. During mating, the male sends waves of
spermatophores down one of his arms -- the hectocotylus
-- into the female's mantle cavity to fertilize
her eggs. Copulation may last for several hours,
and the same pair may mate several times over a
period of week or so.
Eggs are laid in shallow water. On rocky
shores, females find a hole, crevice or sheltered
place and often protect their nests with shells,
stones and other solid objects that they gather.
On sandy or muddy bottom, eggs are laid in empty
mollusc shells or in man-made objects such as
cans, bottles, tires, boots, etc. The total
number of eggs laid varies from 100,000 to
500,000, and it may take up to a week or more for
all eggs to be laid.
The female will not leave her nest in the four
to six weeks that it takes for her eggs to hatch.
Because they rarely eat at all while guarding
their eggs, it is not uncommon for females to die
of starvation. Even in captivity it is almost
impossible to coak a mother octopus away from her
eggs. She may refuse to eat even if food is
dropped right next to her.
care includes cleaning the eggs with the arms
tips and directing jets of water from the funnel
through the strings. The eggs hatch into 1/4-inch
larvae that look like tiny versions of their
parents. They come to rest on the seabed, where
they mature quickly. Larvae prey on plankton
until reaching maturity, at about 45 to 60 days
Octopuses live for about 12 to 18 months in
The octopus has incredible
vision for a marine animal. The well-developed
eyes have a large cornea which gives them a range
of vision of 180 degrees.
The octopus is capable of
learning. In an experiment, octopuses were
trained to distinguish between shapes and to
recognize objects by touch. Other studies have
proven that octopi are capable of solving
problems, with the most well known experiment
showing an octopus opening a jar in order to get
the food inside.
The first writing ink was made
from pigment found in the octopus's ink sac.
genus & species Octopus vulgaris
Animal Diversity Web http://animaldiversity.org/accounts/Octopus_vulgaris/
The Cephalopod Page www.thecephalopodpage.org/Octopusvulgaris.php
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